Astrophysics > Cosmology and Nongalactic Astrophysics

Abstract: (abridged) Here we present HI line and 20-cm radio continuum data of the
nearby galaxy pair NGC1512/1510 as obtained with the Australia Telescope
Compact Array. These are complemented by GALEX UV-, SINGG Halpha- and Spitzer
mid-infrared images, allowing us to compare the distribution and kinematics of
the neutral atomic gas with the locations and ages of the stellar clusters
within the system. For the barred, double-ring galaxy NGC1512 we find a very
large HI disk, about 4x its optical diameter, with two pronounced spiral/tidal
arms. Both its gas distribution and the distribution of the star-forming
regions are affected by gravitational interaction with the neighbouring blue
compact dwarf galaxy NGC1510. The two most distant HI clumps, at radii of about
80 kpc, show signs of star formation and are likely tidal dwarf galaxies. Star
formation in the outer disk of NGC1512 is revealed by deep optical- and
two-color ultraviolet images. Using the latter we determine the properties of
about 200 stellar clusters and explore their correlation with dense HI clumps
in the even larger 2XHI disk. The multi-wavelength analysis of the NGC1512/1510
system, which is probably in the first stages of a minor merger having started
about 400 Myr ago, links stellar and gaseous galaxy properties on scales from
one to 100 kpc.

Comments:

accepted in MNRAS (please find the high-resolution pdf file and further information at this http URL)